Galvanisation of steel sheet, strip, wire or odd shaped steel members is a well known process. There are several known methods, particularly in relation to continuous rigid members in the galvanising industry for in-line processing. However, a difficulty associated with the prior art methods is the requirement of one or more pumping devices for transporting the liquid metal coating from a melting vessel to a galvanising chamber, either directly or indirectly through a holding vessel. Further, with regard to in-line galvanising processes where material is introduced into the galvanising chamber continuously, there needs to be means for preventing molten metal from leaking outside the galvanising chamber. These means are known to take the form of either electromagnetic seals or secondary chambers which house the galvanising chamber so that molten metal is collected in the secondary chamber for eventual return to the holding vessel or melting vessel. Another common prior art method is the trough method, where rigid material is required to be bent or deflected down into a galvanising pot and then slanted upwards thereafter.
Whilst these prior art approaches attempt to improve the operational efficiency and are space saving, they are far from an adequate and economical solution. Recent prior art has considered the use of an induction heating coil to pre-heat the work before entering the galvanising chamber, and the use of electro-magnetic seal rings to prevent the liquid escaping from the galvanising chamber. However, auxiliary equipment is still required, including, a vessel for the purposes of melting zinc or aluminium ingot, a mechanical or electro-magnetic pump to pump the molten zinc/aluminium to the galvanising chamber, and a heating element to maintain galvanising temperature.
As will be appreciated, therefore, there have been various attempts to achieve a successful in-line galvanising of straight products without subjecting them to bending.